EP3529960A1 - Pilotsequenzgenerator und zugehöriges verfahren und kanalschätzer und zugehöriges verfahren - Google Patents

Pilotsequenzgenerator und zugehöriges verfahren und kanalschätzer und zugehöriges verfahren

Info

Publication number
EP3529960A1
EP3529960A1 EP16805842.8A EP16805842A EP3529960A1 EP 3529960 A1 EP3529960 A1 EP 3529960A1 EP 16805842 A EP16805842 A EP 16805842A EP 3529960 A1 EP3529960 A1 EP 3529960A1
Authority
EP
European Patent Office
Prior art keywords
pilot sequence
pilot
user communication
processed
sub
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP16805842.8A
Other languages
English (en)
French (fr)
Other versions
EP3529960B1 (de
Inventor
Nassar KSAIRI
Merouane Debbah
Beatrice TOMASI
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Huawei Technologies Co Ltd
Original Assignee
Huawei Technologies Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Huawei Technologies Co Ltd filed Critical Huawei Technologies Co Ltd
Publication of EP3529960A1 publication Critical patent/EP3529960A1/de
Application granted granted Critical
Publication of EP3529960B1 publication Critical patent/EP3529960B1/de
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00Modulated-carrier systems
    • H04L27/26Systems using multi-frequency codes
    • H04L27/2601Multicarrier modulation systems
    • H04L27/2602Signal structure
    • H04L27/261Details of reference signals
    • H04L27/2613Structure of the reference signals
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00Baseband systems
    • H04L25/02Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202Channel estimation
    • H04L25/0204Channel estimation of multiple channels
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00Baseband systems
    • H04L25/02Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202Channel estimation
    • H04L25/0224Channel estimation using sounding signals
    • H04L25/0226Channel estimation using sounding signals sounding signals per se
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00Arrangements affording multiple use of the transmission path
    • H04L5/003Arrangements for allocating sub-channels of the transmission path
    • H04L5/0048Allocation of pilot signals, i.e. of signals known to the receiver
    • H04L5/0051Allocation of pilot signals, i.e. of signals known to the receiver of dedicated pilots, i.e. pilots destined for a single user or terminal

Definitions

  • the present invention is directed to generation of pilot sequences for uplink and/or downlink transmission.
  • the present invention relates to a pilot sequence generator (i.e. a device configured to generate corresponding pilot sequences) and to a corresponding method.
  • the present invention is directed to channel estimation.
  • the channel estimation is executed by use of the generated pilot sequences.
  • the present invention is directed to a channel estimator (i.e. a device configured to execute the channel estimation) and a corresponding method.
  • CSI channel state information
  • user-specific reference signals or user- specific pilots
  • the CSI that is thus obtained can be used to coherently demodulate the uplink signals sent by the user terminals, as coherent demodulation is known to provide higher spectral efficiencies than non-coherent demodulation.
  • This CSI can also help the BS take scheduling decisions for subsequent transmissions to/from the user terminals to determine which of them transmit/receive on which time-frequency radio resources.
  • the BS has multiple antennas
  • multiple (co-scheduled) users can transmit on the same time-frequency resources to the BS using multiuser multiple-input multiple-output (MU-MIMO) techniques, thus creating interference for each other's signal at the BS side.
  • the CSI obtained from user- specific pilots is used by the BS to help in the detection of the signal of each one of the co- scheduled users.
  • One practical MU-MIMO uplink scheme is spatial linear combining (also called receive beamforming) which consists in multiplying the signals received at the BS antennas with user and antenna dependent coefficients that are selected based on the CSI of the co-scheduled users, and then in adding (combining) the resulting signals before passing them to the signal detection and modulation module.
  • CSI acquired at the multi-antenna BS thanks to uplink user- specific pilots can be exploited in the reverse transmission, i.e. in the downlink, as CSI at the transmitter (CSIT), which again allows improving performance when simultaneously transmitting to spatially multiplexed user terminals using MU-MIMO techniques.
  • CSIT CSI at the transmitter
  • spatial linear precoding also called beamforming
  • each user terminal can get its useful signal with sufficient strength while undergoing attenuated interference from the signals intended to the other co-scheduled users.
  • pilots are sent by the BS in MU-MIMO systems that employ downlink spatial precoding and they pass through the same precoding that the BS applies to data symbols.
  • user terminals can learn their respective effective downlink channels, i.e. the scalar channel that is experienced at the terminal side as a result of applying spatial precoding at the BS side.
  • This knowledge of the effective downlink channel is necessary for equalization and coherent demodulation purposes at the user terminals.
  • the resources (in time and/or frequency) devoted to user-specific pilots are subtracted from those used for data transmission and thus represent an overhead for the wireless system.
  • this overhead is even larger since user-specific pilots are multiplexed on the same time-frequency resources and thus their length should be made to increase with the number of user terminals that are co-scheduled on these resources. Otherwise, the quality of channel estimation based on user-specific pilots might suffer severe degradation due to excessive interference among the pilot sequences. If the number of user terminals that need to be served on the same time-frequency resources with MU-MIMO is very large, the pilot overhead might significantly reduce the spectral efficiency and ultimately the achievable data rates of these users. The need to simultaneously serve such a large number of user terminals could arise in scenarios of practical interest.
  • One example is the multi-service scenario in which the BS is required to serve a large number of machine-to-machine (M2M) connections while continuing to support the more conventional broadband links to/from user handheld terminals.
  • M2M machine-to-machine
  • Another example is the crowd scenario in which the BS needs to operate in an area with a very dense deployment of user terminals, such as a sports venues, for example.
  • Using state-of-the- art user-specific pilots in such situations could result in a severe reduction of the system throughput and of the achievable data rates of the individual links due to excessive pilot overhead and/or to degraded CSI.
  • the object of the present invention is improving the generation of pilot sequences for an uplink and/or for a downlink transmission.
  • the invention allows generation of pilot sequences for a large number of user terminals by maintaining the system throughput and/or achievable data rates of (individual) data transmission links.
  • the generation of pilot sequences, implemented according to the present invention is intended to avoid the reduction of the system throughput and/or of the achievable data rates of (individual) data transmission links.
  • the present invention proposes a pilot construction and, thus, a multiplexing method for both uplink and downlink user-specific reference signals.
  • the proposed method makes use of the code domain in the aim of creating different sub-sets of pilots.
  • One of these sub-sets is made up of sequences that are orthogonal both to each other and to the other pilot sub-sets.
  • the users that are assigned pilots from this sub-set will be interference free and will get the best possible channel estimation quality, but their maximum number will be limited due to the orthogonality constraint.
  • the other sub-sets are also orthogonal to each other but are made up of sequences that are non-orthogonal in a controlled manner. A controlled non-orthogonality leads on one hand to a controlled degradation of the channel estimation quality.
  • a pilot sequence generator is provided that is arranged to generate pilot sequences for an uplink and/or for a downlink transmission, wherein the pilot sequence generator is configured to: generate a pilot sequence set comprising M+1 pilot sequence subsets, wherein M is a positive integer that is equal to or greater than one, wherein each pilot sequence sub-set of the M+1 pilot sequence sub-sets is orthogonal or at least partially orthogonal to each further pilot sequence sub-set of the M+ 1 pilot sequence sub-sets; assign the M+1 pilot sequence sub-sets to M+1 groups of user communication devices, wherein each pilot sequence sub-set of the M+1 pilot sequence sub-sets is assigned to one group of user communication devices, wherein each group of user communication devices comprises one or more user communication devices, and wherein, by the assignment, the one
  • each pilot sequence sub-set of the M+1 pilot sequence sub-sets is orthogonal or at least partially orthogonal in the code domain, frequency domain and/or time domain to each further pilot sequence sub-set of the M+1 pilot sequence sub-sets.
  • the pilot sequence generator is configured to execute the assignment based on criteria including at least one of the following: user communication device service requirements, user communication device channel conditions, including channel statistics, user communication device position within the cell and/or user communication device distance to a serving base station.
  • the assigning comprises, for each pilot sequence sub-set of the M+1 pilot sequence sub-sets, assigning pilot sequences of the pilot sequence subset to the one or more user communication devices of the group of user communication devices, which is assigned to the pilot sequence sub-set.
  • the pilot sequence generator is configured to execute the assignment by permitting the one or more user communication devices of a group of user communication devices of the M+1 groups of user communication devices to select their own pilot sequences out of the pilot sequences of the pilot sequence sub-set assigned to the group of user communication devices.
  • the pilot sequence generator is configured to generate the pilot sequence set comprising the M+1 pilot sequence sub-sets by executing the following: dividing an initial pilot sequence set, comprising orthogonal or at least partially orthogonal pilot sequences, in a non-processed pilot sequence sub-set and M to-be-processed pilot sequence sub-sets; and generating M processed non-orthogonal pilot sequence sub-sets, wherein the processing unit is configured, for each to-be-processed pilot sequence sub-set of the M to-be-processed pilot sequence sub-sets, to generate a processed non-orthogonal pilot sequence sub-set by multiplying a to-be-processed pilot sequence sub-set matrix, comprising pilot sequences of the respective to-be-processed pilot sequence sub-set as columns, with a complex matrix, wherein columns of matrix resulting from the multiplication represent the respective processed non-orthogonal pilot sequence sub-
  • the non-processed pilot sequence sub-set comprises at least one pilot sequence, and/or wherein each to-be-processed pilot sequence sub-set of the M to-be-processed pilot sequence sub-sets comprises at least two pilot sequences.
  • a first to-be-processed pilot sequence sub-set of the M to-be-processed pilot sequence sub-sets has a number of pilot sequences that is different from a number of pilot sequences of a second to-be-processed pilot sequence sub-set of the M to-be-processed pilot sequence sub-sets, and/or wherein a first processed non-orthogonal pilot sequence sub-set of the M processed non-orthogonal pilot sequence sub-sets has a number of pilot sequences that is different from a number of pilot sequences of a second processed non-orthogonal pilot sequence sub-set of the M processed non-orthogonal pilot sequence sub-sets.
  • the non-processed pilot sequence sub-set is empty and all the generated pilot sequences are in the M processed non-orthogonal pilot sequence sub-sets.
  • the non-processed pilot sequence sub-set comprises at least two pilot sequences, and wherein each one of the pilot sequences of the non-processed pilot sequence sub-set is orthogonal to each further pilot sequence of the non-processed pilot sequence sub-set.
  • each one of the pilot sequences of the non-processed pilot sequence sub-set is orthogonal in the code domain, frequency domain and/or time domains to each further pilot sequence of the non- processed pilot sequence sub-set.
  • the number of rows of the complex matrix is equal to the number of columns of the to-be-processed pilot sequence sub-set matrix, comprising pilot sequences of the respective to-be-processed pilot sequence sub-set as columns, and wherein a number of columns of the complex matrix is greater than the number of rows of the complex matrix.
  • the pilot sequence generator is configured to execute said assigning by assigning pilot sequences of the non-processed pilot sequence sub-set to a first group of user communication devices of the M+l groups of user communication devices and by assigning pilot sequences of each processed non-orthogonal pilot sequence sub-set of the M processed non-orthogonal pilot sequence sub-sets to a corresponding further group of user communication devices of the M+l groups of user communication devices.
  • the pilot sequence generator is configured to transmit a signaling message to a user communication device of a group of user communication devices of the M+l groups of user communication devices, wherein the signaling message comprises an index of a look-up table, storing a plurality of pilot sequences, and an index of a pilot sequence of the look-up table to be used by the user communication device.
  • a method is provided that is arranged to generate pilot sequences for an uplink and/or for a downlink transmission wherein the method comprises the following steps of: generating a pilot sequence set comprising M+l pilot sequence sub-sets, wherein M is a positive integer that is equal to or greater than one, wherein each pilot sequence sub-set of the M+l pilot sequence sub-sets is orthogonal or at least partially orthogonal to each further pilot sequence sub-set of the M+l pilot sequence sub-sets; assigning the M+l pilot sequence sub- sets to M+l groups of user communication devices, wherein each pilot sequence sub-set of the M+l pilot sequence sub-sets is assigned to one group of user communication devices, wherein each group of user communication devices comprises one or more user communication devices, and wherein, by the assignment, the one or more user communication devices of each group of user communication devices of the M+l groups of user communication devices are configured to use, for the uplink and/or for the downlink transmission, pilot sequences of the pilot sequence sub-
  • a channel estimator is provided that is arranged to execute a channel estimation with regard to pilot sequences generated by a pilot sequence generator described herein, wherein the channel estimator is configured to estimate a channel of a user communication device, to which a pilot sequence of a processed non-orthogonal pilot sequence sub-set of the M processed non-orthogonal pilot sequence sub-sets has been assigned, by executing one of the following: a single user channel estimation method by use of one or more signal samples received in response to a transmission of symbols of the pilot sequence and by use of a single column of the complex matrix, which has been used for generating the processed non-orthogonal pilot sequence sub-set of the M processed non-orthogonal pilot sequence sub- sets, wherein the single column is a column of the complex matrix that has been used to generate the pilot sequence, and by use of the to-be-processed pilot sequence sub-set of the pilot sequence
  • a method is provided that is arranged to execute a channel estimation with regard to pilot sequences generated by a pilot sequence generator described herein, wherein the method comprises an estimation of a channel of a user communication device, to which a pilot sequence of a processed non-orthogonal pilot sequence sub-set of the M processed non-orthogonal pilot sequence sub-sets has been assigned, said estimation comprising one of the following: execution of a single user channel estimation method by use of one or more signal samples received in response to a transmission of symbols of the pilot sequence and by use of a single column of the complex matrix, which has been used for generating the processed non-orthogonal pilot sequence sub-set of the M processed non- orthogonal pilot sequence sub-sets, wherein the single column is a column of the complex matrix that has been used to generate the pilot sequence, and by use of the to-be-processed pilot sequence sub-set of the pilot sequences, based on which the processed non-orthogonal pilot sequence sub-set has been generated; execution of
  • each instruction of the one or more instructions comprises an index of a look-up table, storing a plurality of pilot sequences, and an index of a pilot sequence of the look-up table to be used by the user communication device.
  • the user communication device comprises a transmitting entity configured to transmit the symbols of the pilot sequence selected by the processing entity.
  • user communications device comprising: a plurality of look-up tables, wherein in each look-up table of the plurality of look-up tables a plurality of pilot sequences is stored, wherein the plurality of pilot sequences is generated by executing the method of claim 15, and wherein a first plurality of pilot sequences of a first look-up table is generated by executing the method of claim 14 by applying a first M value, which is different from a second M value used for generating a second plurality of pilot sequences of a second look-up table of the plurality of look-up tables, and/or by applying a first complex matrix, which is different from a second complex matrix used for generating the second plurality of pilot sequences of the second look-up table; a receiver adapted to receive instructions from the pilot sequence generator; a processing unit configured to select, based on the received instructions, a pilot sequence from said plurality of stored pilot sequences.
  • Fig. 1 shows an exemplary arrangement of a pilot sequence generator according to an embodiment of the present invention.
  • Fig. 2 shows steps executed by the pilot sequence generator according to an embodiment of the present invention.
  • Fig. 3 shows an exemplary assignment of M+l pilot sequence sub-sets to M+l groups of communication devices according to an embodiment of the present invention.
  • Fig. 4 shows exemplary sub-steps of the pilot sequence set generation step according to an embodiment of the present invention.
  • Fig. 5 shows an exemplary execution of pilot sequence generation according to an embodiment of the present invention.
  • Fig. 6 shows exemplary sequences of steps executed according to an embodiment of the present invention, said steps starting from pilot sequence generation and ending at channel estimation.
  • Fig. 7 shows an exemplary arrangement of a channel estimator according to an embodiment of the present invention.
  • Fig. 8 shows steps executed by the channel estimator according to an embodiment of the present invention.
  • Fig. 9 shows a generation of user communication device specific pilot sequences from orthogonal cover codes (OCCs) according to an embodiment of the present invention, wherein the number of user communication device specific pilot sequences is larger than the number of OCCs.
  • OCCs orthogonal cover codes
  • Fig. 10 shows a generation of user communication device specific pilot sequences from cyclic shift (CS) sequences according to an embodiment of the present invention, wherein the number of user communication device specific pilot sequences is larger than the number of CS sequences.
  • CS cyclic shift
  • Fig. 11 shows a look-up table, arranged to store a plurality of pilot sequences, according to an embodiment of the present invention.
  • Fig. 12 shows an exemplary arrangement of a user communication device according to an embodiment of the present invention.
  • Fig. 1 shows an exemplary arrangement of a pilot sequence generator 1 according to an embodiment of the present invention.
  • the pilot sequence generator 1 is arranged to generate pilot sequences for uplink and/or for downlink transmissions.
  • the pilot sequence generator 1 comprises a transmitting entity 12, configured to execute transmission of data, and a receiving entity 13, configured to execute reception of data.
  • the transmitting entity 12 and the receiving entity 13 are provided as one entity (e.g., transceiver), as indicated in Fig. 1 by the box with dashed lines.
  • any one of the transmission steps, which is described herein as being executed by the pilot sequence generator 1 is particularly executed by the transmitting entity 12.
  • Any one of the reception steps, which is described herein as being executed by the pilot sequence generator 1, is particularly executed by the receiving entity 13.
  • the pilot sequence generator 1 comprises one or more processing entities 11 configured to execute different processing steps, except for the transmission and reception of data, which are executed accordingly by the transmitting entity 12 and the receiving entity 13.
  • any one of the steps, which is described herein as being executed by the pilot sequence generator 1 and which does not refer to data transmission or reception, is particularly executed by at least one of the one or more processing entities 11.
  • the presence of the transmitting entity 12, receiving entity 13 and/or transceiver in the pilot sequence generator 1 is optional. Their presence is implementation- specific and depends on the environment of the pilot sequence generator 1 and/or its further functions in a particular implementation of the pilot sequence generator 1.
  • Fig. 2 shows steps 21, 22 executed by the pilot sequence generator 1 according to an embodiment of the present invention. Said steps 21, 22 are executed for generating pilot sequences for an uplink and/or a downlink transmission. Steps 21 , 22 are executed, for example, by the one or more processing entities 11 of the pilot sequence generator 1.
  • the pilot sequence generator 1 generates a pilot sequence set with M+ 1 pilot sequence sub-sets, wherein M is a positive integer that is equal to or greater than one.
  • each pilot sequence sub-set is orthogonal or at least partially orthogonal to each further pilot sequence sub-set of the M+l pilot sequence sub-sets of said pilot sequence set.
  • each pilot sequence sub-set is orthogonal or at least partially orthogonal in the code domain, frequency domain and/or time domain to each further pilot sequence sub-set of the M+l pilot sequence sub-sets of said pilot sequence set.
  • the pilot sequence generator 1 assigns the M+l pilot sequence sub-sets to M+l groups of user communication devices, wherein each pilot sequence sub-set of the M+l pilot sequence sub-sets is assigned to one group of user communication devices.
  • each group of user communication devices comprises one or more user communication devices.
  • the one or more user communication devices of each group of user communication devices are configured to use, for the uplink and/or for the downlink transmission, pilot sequences of the pilot sequence sub-set assigned to the respective group of user communication devices.
  • the user communication devices comprise any kind of user communication devices.
  • user communication devices comprise static and/or mobile communication devices.
  • the user communication devices comprise communication devices that are involved in an IoT communication.
  • the present invention is not limited by a specific kind of user communication devices.
  • the user communication devices comprise devices that do not constitute a communication network, but use the communication network for communication purposes.
  • the assignment 22 is based on criteria including at least one of the following: user communication device service requirements, user communication device channel conditions, user communication device position within the cell and/or user communication device distance to a serving base station.
  • one or more i.e.
  • the assigning 22 comprises, for each pilot sequence sub-set of the M+1 pilot sequence sub-sets, assigning 22 pilot sequences of the pilot sequence sub-set to the one or more user communication devices of the group of user communication devices, which is assigned to the pilot sequence sub-set.
  • the pilot sequence generator 1 is configured to execute the assignment 22 by permitting the one or more user communication devices of a group of user communication devices of the M+1 groups of user communication devices to select their own pilot sequences out of the pilot sequences of the pilot sequence sub-set assigned to the group of user communication devices.
  • Fig. 3 shows an exemplary assignment of M+1 pilot sequence sub-sets to M+1 groups of communication devices according to an embodiment of the present invention.
  • One or more, i.e. any one of features explained by use of Fig. 3 are combinable with one or more, i.e. any one of the embodiments described herein.
  • Fig. 3 shows a result of a pilot sequence generation (see, for example, steps of Fig. 2) executed by the pilot sequence generator 1.
  • a pilot sequence set 31 has been generated 21 by the pilot sequence generator 1.
  • the generated 21 pilot sequence set 31 comprises M+1 pilot sequence sub-sets 311_1 , 311_2, ..., 311_M+1 , wherein M is an integer and M > 1.
  • the M+1 pilot sequence sub-sets 311 1 , 311 2, 311_M+1 are generated 21 such that they are orthogonal or at least partially orthogonal to each other.
  • the M+1 pilot sequence sub-sets 311 1, 311 2, ..., 31 l M+l may comprise different numbers of user communication devices. I.e.
  • each pilot sequence sub-set 311 1, 311 2, ..., 311_M+1 may comprise a number of pilot sequences that it different from a number of pilot sequences of at least one further pilot sequence sub-set 311 1, 311 2, ..., 311_M+1.
  • M+1 groups 32 1, 32_2, 32_M+1 of user communication devices are present according to the embodiment of Fig. 3.
  • Each one of the M+1 groups 32 1, 32_2, 32_M+1 of user communication devices comprises one or more user communication devices.
  • the M+l groups 32 1, 32_2, 32_M+1 of user communication devices comprise different numbers of user communication devices.
  • each group 32 1, 32 2, ..., 32 M+1 of user communication devices comprises a number of user communication devices that is different from a number of user communication devices of at least one further group 32 1, 32_2, ..., 32_M+1 of user communication devices.
  • Fig. 4 shows exemplary sub-steps 41, 42 of the pilot sequence set 31 generation step 21 according to an embodiment of the present invention.
  • the embodiment of Fig. 4 can be seen as an embodiment that supplements the above-described embodiments.
  • one or more, i.e. any one of the features of the embodiment of Fig. 4 are combinable with one or more, i.e. any one of the embodiments described herein.
  • the pilot sequence generator 1 when generating 21 the pilot sequence set 31, the pilot sequence generator 1 divides 41 an initial pilot sequence set, comprising orthogonal or at least partially orthogonal pilot sequences, in a non-processed pilot sequence sub-set and M to-be- processed pilot sequence sub-sets.
  • each pilot sequence of the initial pilot sequence set is orthogonal or at least partially orthogonal (e.g., in the code domain, frequency domain and/or time domain) to each further pilot sequence in the initial pilot sequence set.
  • the non-processed pilot sequence sub-set comprises at least on pilot sequence
  • each to-be-processed pilot sequence sub-set of the M to-be-processed pilot sequence subsets comprises at least two pilot sequences.
  • the M to-be-processed pilot sequence sub-sets are arranged such that at least one to-be-processed pilot sequence sub-set of the M to-be-processed pilot sequence sub-sets has a number of pilot sequences that is different from a number of a pilot sequences of at least one another to-be-processed pilot sequence subset of the M to-be-processed pilot sequence sub-sets. Additionally, according to an embodiment combinable with one or more, i.e.
  • the non- processed pilot sequence sub-set comprises at least two pilot sequences and each one of the pilot sequences of the non-processed pilot sequence sub-set is orthogonal to each further pilot sequence of the non-processed pilot sequence sub-set.
  • each one of the pilot sequences of the non-processed pilot sequence sub-set is orthogonal in the code domain, frequency domain and/or time domain to each further pilot sequence of the non-processed pilot sequence sub-set.
  • the pilot sequence generator 1 uses the M to-be-processed pilot sequence sub-sets to generate M processed non-orthogonal pilot sequence sub-sets.
  • the pilot sequence generator 1 executes with regard to each to-be-processed pilot sequence sub-set of the M to-be-processed pilot sequence sub-sets the following: the pilot sequence generator 1 generates for the respective to-be-processed pilot sequence sub-set a processed non-orthogonal pilot sequence sub-set by multiplying a to-be-processed pilot sequence sub-set matrix, comprising pilot sequences of the respective to-be-processed pilot sequence sub-set as columns, with a complex matrix.
  • the columns of matrix resulting from the respective multiplication represent the respective processed non-orthogonal pilot sequence subset.
  • the number of rows of the complex matrix is equal to the number of columns of the to-be-processed pilot sequence sub-set matrix, comprising pilot sequences of the respective to-be-processed pilot sequence sub-set as columns, and a number of columns of the complex matrix is greater than the number of rows of the complex matrix.
  • non-orthogonal pilot sequence sub-set means that the pilot sequences of the respective sub-set are not orthogonal (e.g., in code domain, in time domain and/or in frequency domain) to each other.
  • each non-orthogonal pilot sequence sub-set of the M non-orthogonal pilot sequence sub-sets is orthogonal (e.g., in code domain, in time domain and/or in frequency domain) to each other non-orthogonal pilot sequence sub-set of the M non- orthogonal pilot sequence sub-sets.
  • At least one processed non-orthogonal pilot sequence sub-set of the M processed non-orthogonal pilot sequence sub-sets has a number of pilot sequences that is different from a number of pilot sequences of at least one further processed non-orthogonal pilot sequence sub-set of the M processed non-orthogonal pilot sequence sub-sets.
  • the non-processed pilot sequence sub-set, resulting from the execution of step 41, and the M processed non-orthogonal pilot sequence sub-sets, resulting from the execution of step 42, represent the M+l pilot sequence sub-sets 311_1, 311 2, 311_M+1 of the generated 21 pilot sequence set 31.
  • the M+l pilot sequence sub-sets i.e. the non-processed pilot sequence sub-set and the M processed non-orthogonal pilot sequence sub-sets
  • 311 1, 311 2, 311_M+1 are assigned 22 to the M+l groups 32 1, 32_2, 32_M+1 of user communication devices.
  • Fig. 5 shows an exemplary execution of pilot sequence generation according to an embodiment of the present invention.
  • the embodiment of Fig. 5 shows some specific arrangement of the features of the present invention. It has to be pointed out that one or more, i.e. any one of the features of the embodiment of Fig. 5 are combinable with one or more, i.e. any one of the embodiments described herein.
  • a baseline code matrix U composed of N orthogonal or at least partially orthogonal columns is provided as an initial pilot sequence set 31 ', wherein the N columns of the code matrix U represent the initial pilot sequences of the initial pilot sequence set 3 ⁇ .
  • the orthogonality is considered, for example, in the time, frequency and/or code domain.
  • matrix U is divided 41 in a non-processed pilot sequence sub-set 311 1, represented in Fig. 5 by matrix U orth , and in one to-be-processed pilot sequence sub-set 311 2', represented in Fig. 5 by matrix jjnon-orth
  • M is composed of N orth columns or N orth
  • orthogonal pilot sequences which are orthogonal among each other
  • u non_ortn is composed of jV non_ortn columns or jV non_ortn non-orthogonal pilot sequences.
  • the columns (i.e. pilot sequences) of U orth and the columns (i.e. pilot sequences) of u non_orth are orthogonal to each other.
  • the abbreviation "orth” stands for “orthogonal”
  • non-orth stands for “non-orthogonal” or “not orthogonal”, respectively.
  • non-orthogonal user communication devices means that the respective user communication devices of the second group of communication devices will get assigned 22 non-orthogonal pilot sequences. Indeed, each "non-orth" pilot sequence is a linear combination of all the columns of u non_ortn with coefficients that are taken from one of the columns of W non_ortn .
  • the matrix representing the to-be-processed pilot sequence sub-set 311 2 ' is multiplied with the complex matrix 5 to obtain a processed non-orthogonal pilot
  • sequence set 311 2 represented by Columns of the matrix
  • orthogonal pilot sequence set 311 2 Due to this non-orthogonality, the channel estimation step for each "non-orthogonal" user communication device at the base station will undergo interference/contamination from the signals of the other "non-orthogonal" transmissions. However, a proper choice of W non_orth (and implicitly of as well as the use of joint channel estimation for the
  • non-orthogonal user communication devices will help keep this contamination at controlled levels. Moreover, thanks to the orthogonality between the sub-matrices or sub-sets U orth and U non_orth , the non-orthogonality of the "non-orthogonal" user communication devices will cause no interference/contamination to the pilot sequences of the "orthogonal" user communication devices.
  • the present invention increases the number of generated pilots and also the number of user communication devices that can be simultaneously served.
  • Each one of these pilot sequences is composed of a number of pilot symbols equal to Since the inequality
  • Fig. 6 shows exemplary sequences of steps executed according to an embodiment of the present invention, said steps starting from pilot sequence generation and ending at channel estimation.
  • the exemplary sequences of steps are implementable, for example, in MU-MIMO where user communication device specific pilot sequences are generated.
  • Fig. 6 is based on the above-described embodiments and, in particular, supplements them. It has to be pointed out that one or more, i.e. any one of the features of the embodiment of Fig. 6 are combinable with one or more, i.e. any one of the embodiments described herein.
  • the embodiment of Fig. 6 is exemplary based on the embodiment of Fig. 5.
  • columns of the matrix U orth (being the non-processed pilot sequence sub-set 31 1 1) of Fig. 5 are used as signatures to distinguish between the channels of the different (orthogonal) user communication devices 321 1 , 32 l_k of the first group 32 1 of user communication devices.
  • columns of matrix w non_orth are used as signatures to distinguish between the channels of the different (non-orthogonal) user communication devices 322 1 , . .. , 322_z of the second group of user communication devices.
  • One way of selecting vv non- ° is thus such that the minimum cross-correlation among its columns is as low as possible.
  • Fig. 6 visualizes the utilization of the generated pilot sequence sub-sets.
  • a non-processed pilot sequence sub-set 311 1 or matrix U orth respectively has been obtained by executing step 41 on the initial pilot sequence set or matrix U respectively, and the pilot sequences of the non-processed pilot sequence sub-set 311 1 or columns of matrix U orth respectively have been assigned 22 to the first group 32 1 of user communication devices 321 1, ..., 32 l_k.
  • the number k of the pilot sequences of the non-processed pilot sequence sub-set 311 1 or columns of matrix U orth respectively corresponds to the number k of the user communication devices 321 1, 32 l_k of the first group 32 1 of user communication devices.
  • Each i-th (1 ⁇ i ⁇ k) user communication device 321 1, 32 l_k of the first group 32 1 of user communication devices transmits one respective pilot sequence to BS 62 via a respective uplink channel (e.g., MU-MOMO uplink channel) 61, wherein the respective pilot sequence corresponds to a respective (i.e. i-th) column of the matrix U orth .
  • a respective uplink channel e.g., MU-MOMO uplink channel
  • a processed non-orthogonal pilot sequence sub-set 311 2 or matrix u non_orth x respectively has been obtained by executing step 42, and the pilot sequences of the processed non-orthogonal pilot sequence sub-set 311 2 or the columns of the matrix respectively have been assigned 22 to the second group 32_2 of user
  • the number z of the pilot sequences of the processed non-orthogonal pilot sequence sub-set 311 2 or columns of matrix r eS p ec ti V ely corresponds to the number z of the user communication
  • Each j-th (1 ⁇ j ⁇ z) user communication device 322 1, 322_z of the second group 32 2 of user communication devices transmits one respective pilot sequence to BS 62 via a respective uplink channel (e.g., MU-MOMO uplink channel) 61, wherein the respective pilot sequence corresponds to a respective (i.e. j-th) column of the matrix only the matrix W non 0 is indicated for sake of simplicity of Fig. 6 because the number of columns of w non -° rth is the same as the number of columns of i.e. z.
  • a respective uplink channel e.g., MU-MOMO uplink channel
  • the BS 62 uses combining/precoding schemes that are aware of the "orthogonal" and "non- orthogonal" grouping of user communication devices. In this way, one can maintain the effect of the by-design pilot contamination within the "non-orthogonal" group 32 2 leaving the "orthogonal" group 32 1 contamination free.
  • One example of such combining/precoding is single-user detection/precoding at the BS 62.
  • signaling only a slight modification of existing pilot assignment bits in scheduling grants and radio resource control (RRC) messages in current wireless communications standards is needed. This change only incurs log 2 (K)— log 2 (N) additional bits in these signaling messages.
  • the BS 62 executes channel estimation for the user communication devices 321 1 , 32 l_k of the first or "orthogonal" group 32 1 of user communication devices 321 1 , . .. , 321_k based on the pilot sequences
  • the BS 62 is configured to execute any one of conventional channel estimation methods, e.g. a legacy channel estimation as indicated in Fig. 6.
  • the BS 62 executes channel estimation for the respective user communication devices 322 1 , . .. , 322_z based on pilot sequences of the processed non-orthogonal pilot sequence subset 31 1 2, said pilot sequences being the columns of the matri
  • the BS 62 is configured to execute a joint channel estimation method as indicated in Fig. 6.
  • the joint channel estimation method comprises, for example, a multiuser least squares (LS) method or multiuser minimum mean square error (MMSE) method, both being well known and, therefore, being not described in more detail herein.
  • LS multiuser least squares
  • MMSE multiuser minimum mean square error
  • the BS 62 itself can be seen as a channel estimator or the BS 62 comprises a channel estimator as a component of the BS 62.
  • the scheme used herein is a hybrid (orthogonal/non-orthogonal) sequence construction and multiplexing method that allows to precondition the user communication device specific pilot sequences of a number of user communication devices 321 1, ..., 321_k, 322_1, ..., 322_z in a way that they can be sent using a much smaller number of orthogonal codes or pilot sequences respectively.
  • pilot sequence transmission scheme is the possibility of multiplexing the user communication device specific pilots of a much larger number of simultaneous connections than what can be accommodated with existing solutions while requiring the same pilot overhead as them, thus allowing the BS 62 to communicate simultaneously with larger numbers of connected user communication devices 321 1, ..., 321_k, 322 1 , ... , 322_z. This is done while guaranteeing the best possible channel estimation precision for one category of user communication devices 321 1, 321_k, 322_1, 322_z, typically those with broadband/high data rate requirements, who need the most such channel estimation quality. This performance is not possible with existing solutions which can only accommodate a small number of simultaneous connections with accepted channel estimation quality and which result in severe degradation of this quality if the number of simultaneous connections is increased.
  • Another advantage is the possibility of increasing the system throughput as compared to existing user communication device specific pilot multiplexing solutions by means of reducing the average pilot overhead needed to communicate with the active devices in the system. Again, this is achieved while maintaining for a sub-set of user communication devices, e.g., those running broadband services, the best possible channel estimates. As shown below in more detail, with numerical results, that neither purely orthogonal nor purely non-orthogonal user-specific pilot sequences can outperform the proposed design in terms of system throughput.
  • the novel hybrid orthogonal/non- orthogonal pilot sequence construction is guaranteed to achieve a sum data rate that is at worst equal to, but typically larger than, the sum data rate of existing solutions.
  • the present invention provides a method to simultaneously transmit a (possibly large) number of user specific reference signals that are needed either by the base station 62 of a wireless system to acquire uplink channel state information from a possibly large number of user communication devices 321_1 , ... , 32 l_k, 322 1 , ... , 322_z that are scheduled on the same time-frequency resources; or by these user communication devices 321 1, 321_k, 322_1, 322_z to learn their respective effective downlink channels.
  • the user communication devices 321 1, 321_k, 322_1, 322_z may belong to different service classes with different quality of service requirements.
  • the method consists in creating M+l>2 sub-sets of communication device specific pilot sequences starting from a set of orthogonal sequences 31 '. These sub-sets will be assigned in a flexible manner to M+l distinct groups 32 1, 32_2, 32_M+1 of user communication devices 321 1, 321_k, 322_1, 322_z, each possibly with a different service requirement.
  • the method uses a hierarchical spreading technique to achieve the following.
  • the pilots of the first sub-set or the non-processed pilot sequence sub-set 311 1 respectively are orthogonal to each other by design, resulting in the best possible channel estimation quality for the first group 32 1 of user communication devices 321 1, ..., 32 l_k.
  • the pilot sequences of each of the remaining M sub-sets or to-be-processed pilot sequence subsets are non-orthogonal to each other, thus allowing to serve larger numbers of simultaneous connections in their respective user communication device groups by means of overloading their available resources.
  • This overloading causes contamination (interference) among the pilot sequences.
  • contamination can be maintained within a controlled level by proper tuning of the scheme parameters.
  • Different degrees of overloading can be used in user communication device groups 32 1, 32 2, 32_M+1 that have possibly different service requirements.
  • the M+l pilot sequence sub-sets 311 1, 311 2, 311 M+1 are additionally orthogonal to each other by design, so that there is no inter-group pilot contamination. This means that overloading in the M non-orthogonal sub-sets 311 2, 311 M+1 does not affect channel estimation quality for user communication devices in the first orthogonal group 311 1.
  • Fig. 7 shows an exemplary arrangement of a general channel estimator 7 according to an embodiment of the present invention.
  • the channel estimator 7 is arranged to execute channel estimation as described herein.
  • Fig. 7 supplements the embodiments described herein. It has to be pointed out that one or more, i.e. any one of the features of the embodiment of Fig. 7 are combinable with one or more, i.e. any one of the embodiments described herein.
  • the channel estimator 7 comprises a transmitting entity 72, configured to execute transmission of data, and a receiving entity 73, configured to execute reception of data.
  • the transmitting entity 72 and the receiving entity 73 are provided as one entity (e.g., transceiver), as indicated in Fig. 7 by the box with dashed lines.
  • any one of the transmission steps, which is described herein as being executed by the channel estimator 7, is particularly executed by the transmitting entity 72.
  • Any one of the reception steps, which is described herein as being executed by the channel estimator 7, is particularly executed by the receiving entity 73.
  • the channel estimator 7 comprises one or more processing entities 71 configured to execute different processing steps, except for the transmission and reception of data, which are executed accordingly by the transmitting entity 72 and the receiving entity 73.
  • any one of the steps, which is described herein as being executed by the channel estimator 7 and which does not refer to data transmission or reception, is particularly executed by at least one of the one or more processing entities 71.
  • the presence of the transmitting entity 72, receiving entity 73 and/or transceiver in the pilot sequence generator 7 in the channel estimator 7 is optional. Their presence is implementation-specific and depends on the environment of the channel estimator 7 and/or its further functions in a particular implementation of the channel estimator 7.
  • Fig. 8 shows two alternative steps 81, 82 executed by the channel estimator 7 according to an embodiment of the present invention. Said alternative steps 81, 82 are particularly executed by the channel estimator 7 to estimate a channel of a user communication device 322 1, ..., 322_z to which a pilot sequence of a processed non-orthogonal pilot sequence sub-set 311 2 of the M processed non-orthogonal pilot sequence sub-sets has been assigned.
  • Fig. 8 supplements the embodiments described herein. It has to be pointed out that one or more, i.e. any one of the features of the embodiment of Fig. 8 are combinable with one or more, i.e. any one of the embodiments described herein.
  • the channel estimator 7 executes a single user channel estimation method by use of one or more signal samples received in response to a transmission of symbols of the pilot sequence of the processed non-orthogonal pilot sequence sub-set 311 2 and by use of a single column of the complex matrix 5, which has been used for generating the processed non-orthogonal pilot sequence sub-set 311 2 of the M processed non-orthogonal pilot sequence sub-sets, wherein the single column is a column of the complex matrix that has been used to generate the pilot sequence, and by use of the to-be-processed pilot sequence sub- set 311 2' of the pilot sequences, based on which the processed non-orthogonal pilot sequence sub-set 311 2 has been generated.
  • the channel estimator 7 executes a joint channel estimation method by use of: the one or more signal samples, the complex matrix 5, and the to- be-processed pilot sequence sub-set 311 2'.
  • Fig. 9 shows a generation of user communication device specific pilot sequences 311 1, 311 2 from orthogonal cover codes (OCCs) 31 ' according to an embodiment of the present invention, wherein the number of user communication device specific pilot sequences 311 1, 311 2 is larger than the number of OCCs 3 ⁇ .
  • Fig. 9 supplements the embodiments described herein. It has to be pointed out that one or more, i.e. any one of the features of the embodiment of Fig. 9 are combinable with one or more, i.e. any one of the embodiments described herein.
  • the matrix U corresponding to the initial pilot sequence set 31 ' is exemplary any N x N orthogonal (OCC) matrix, e.g.
  • the columns of the complex matrix vv non-orth 5 are chosen such that their minimal pairwise angle is as large as possible.
  • any conventional channel estimation method is usable to estimate the channels of user communication devices 321 1, 32 l_k from the "orthogonal" group 32 1 based on the pilot sequences
  • H m the frequency-domain channel coefficient that is desired to be estimated at the BS 61 using the pilot p m . It has to be noted that H m does not depend on the resource element index n because OCC pilot sequences are typically chosen short enough to fit in a region of the resource grid where the channel is almost constant. Let y n designate the received sample at the BS corrupted by both thermal noise z n and interference from other "non-orthogonal" user communication devices pilot sequences. Then, we have
  • M is used to designate the conjugate transpose of M.
  • a better method for channel estimation for "non-orthogonal" pilot sequence subsets 31 1 2 is joint channel estimation 82, such as multiuser least squares (LS) or multiuser minimum mean square error (MMSE), in which all the columns of the matrix vv non-orth 5 are used while estimating the channel responses of all the "non-orthogonal" user communication devices 322_1 , 322_z. More precisely, denote by H the vector of channel coefficients
  • H LS The multiuser LS estimate of H, denoted as H LS , is given by
  • channel estimate of the ⁇ non_ortn "non-orthogonal" user communication devices denoted as can be computed as follows:
  • Rz designates the square root of the covariance matrix R and ⁇ 2 designates the variance of the additive noise z n .
  • Fig. 10 shows a generation of user communication device specific pilot sequences 31 1 1 , 31 1 2 from cyclic shift (CS) sequences 31 ' according to an embodiment of the present invention, wherein the number of user communication device specific pilot sequences 31 1 1 , 31 1 2 is larger than the number of CS sequences 3 ⁇ .
  • Fig. 10 supplements the embodiments described herein. It has to be pointed out that one or more, i.e. any one of the features of the embodiment of Fig. 10 are combinable with one or more, i.e. any one of the embodiments described herein.
  • the matrix U 31 ' used as the basis in our pilot construction is selected as the rectangular matrix whose columns are N CS sequences constructed from the same base sequence.
  • the matrix 5 is exemplary selected by setting its columns to be any 4 points o n a 3-dimensional complex sphere of radius 1 chosen such
  • any conventional CS-based channel estimation method can be used to estimate the channels of user communication devices 321 1 , . .. , 32 l_k from the "orthogonal" group 32 1 based on the pilot sequences u° rth .. As for the "non-orthogonal" group 32_2, the shifted channel
  • impulse responses of the "non-orthogonal" user communication devices 322 1 , . .. , 322_z will still be separable from the impulse responses of the channels of the "orthogonal" user communication devices 321 1 , 32 l_k.
  • each one of the pilot sequences of the "non-orthogonal" user communication devices 322 1 , . .. , 322_z is a linear combination of multiple CS sequences, their respective channel impulse responses will no longer be separable from each other by time domain windowing.
  • the columns of the complex matrix Yynon-orth 5 can ⁇ Q USQ ⁇ to distinguish between the channels of "non-orthogonal" the "non- orthogonal" user communication devices 322 1 , . .. , 322_z by means of coherently combining on a sample basis the jV non-orth shifted versions of each "non-orthogonal" channel impulse response using the corresponding column of the complex matrix 5. More precisely, let p m denote the particular column of matrix (i.e. processed non-
  • orthogonal pilot sequence sub-set 311 2 assigned as the pilot sequence of user communication device m and let N p be the length in symbols of this pilot. Note that by construction:
  • H m n the frequency-domain channel coefficient at the position of the subcarrier n that is desired to be estimated at the BS 62 using the pilot p m and let y n designate the received sample at the BS 62 corrupted by both thermal noise z n and interference from other non-orthogonal user communication device 322 1, 322_z pilot sequences. Then y n writes as where p m n denotes the n-th element (1 ⁇ n ⁇ N p ) of the pilot sequence p m .
  • LS least- squares
  • the present invention relates to generation of pilot sequences for uplink and/or for downlink transmission.
  • a pilot sequence set 31 comprising M+l pilot sequence sub-sets 311_1 , 311_2, ... , 311_M+1 is generated, M being positive integer that is equal to or greater than one (i.e. M>1), each pilot sequence sub-set 311 1 , 311 2, 311_M+1 of the
  • M+l pilot sequence sub-sets 311 1 , 311 2, 311_M+1 being orthogonal or at least partially orthogonal to each further pilot sequence sub-set 311 1, 311 2, ..., 311_M+1 of the M+l pilot sequence sub-sets 311_1 , 311_2, ..., 311_M+1.
  • the M+l pilot sequence sub-sets 311_1 , 311_2, ..., 311_M+1 can have different sizes corresponding to different desired degrees of pilot symbol time/frequency resource overloading and/or different desired degrees of pilot overhead reduction.
  • the M+l pilot sequence sub-sets 311 1 , 311 2, 311_M+1 are assigned to M+l groups 32 1, 32_2, 32_M+1 of user communication devices, wherein each pilot sequence subset 311 1 , 311 2, 311_M+1 is assigned to one group 32 1, 32_2, 32_M+1 of user communication devices, wherein each group 32 1, 32 2, 32 M+1 of user communication devices comprises one or more user communication devices, and wherein, by the assignment, the one or more user communication devices of each group 32 1, 32 2, 32 M+1 of user communication devices are configured to use, for the uplink and/or downlink transmission, pilot sequences of the pilot sequence sub-set 311_1 , 311_2, ..., 311_M+1 assigned to the respective group 32 1, 32_2, 32_M+1 of user communication devices. Additionally, the present invention relates to corresponding channel estimation.
  • some of the advantages achieved by the present invention comprise at least one of the following: allowing the BS 62 to communicate simultaneously with large numbers of connected user communication devices 321 1, 321_k, 322_1, 32_z by enabling the simultaneous transmission of large numbers of user communication device specific pilot sequences; increasing system throughput by reducing the average pilot overhead needed to communicate with the active user communication devices 321 1, ... , 32 l_k, 322 1 , ... , 32_z in the system; achieving the best possible channel estimation quality for user communication devices 321 1, 321_k, 322_1, 32_z who need it, e.g., broadband user communication devices 321 1, ... , 321_k, 322_1, ..., 32_z.
  • Fig. 11 shows a plurality 111 of L look-up tables 1111 1, 1111 2, I l l 1_L, where L is a strictly positive integer, i.e. L>1.
  • L is a strictly positive integer, i.e. L>1.
  • Each one of the L look-up tables 1111 1, 1111 2, ... , 1111_L is arranged to store a plurality of pilot sequences, according to an embodiment of the present invention.
  • the first look-up table 1111 1 comprises a set of orthogonal sequences stored in the
  • the second look-up table 1111 2 comprises a set of orthogonal sequences stored in the matrix another set of orthogonal sequences stored in the matrix
  • the L-th look-up table 1111_L comprises a set of orthogonal sequences stored in the
  • Fig. 12 shows an exemplary arrangement of a user communication device 112 according to an embodiment of the present invention.
  • the user communication device 112 is arranged to use one or more pilot sequences, generated by the pilot sequence generator 1 for uplink and/or for downlink transmissions.
  • the user communication device 112 is an exemplary representative of any of the above mentioned user communication devices 321 1, ... , 32 l_k, 322 1, ... , 32_z.
  • the user communication device 112 comprises a transmitting entity 1122, configured to execute transmission of data and pilot symbols, and a receiving entity 1123, configured to execute reception of data and of pilot symbols.
  • the transmitting entity 1122 and the receiving entity 1123 are provided as one entity (e.g., transceiver), as indicated in Fig. 12 by the box with dashed lines.
  • any one of the transmission steps, which is described herein as being executed by a user communication device 112 is particularly executed by the transmitting entity 1122.
  • Any one of the reception steps, which is described herein as being executed by a user communication device 112 is particularly executed by the receiving entity 1123.
  • the receiving entity is configured to receive instructions from the pilot sequence generator 1.
  • the user communication device 112 comprises one or more data storing entities 1124 configured to store data.
  • the one or more storing entities 1124 is configured to store a plurality 111 of look-up tables 1111 1, 1111 2, 1111 L.
  • a plurality of pilot sequences is stored, wherein the plurality of pilot sequences is generated by the pilot sequence generator 1.
  • a first plurality of pilot sequences of a first look-up table 1111 1 is generated by applying a first M value, which is different from a second M value used for generating a second plurality of pilot sequences of a second look-up table 1111 2, ... , 1111_L of the plurality of look-up tables 111, and/or by applying a first complex matrix which is different from a second complex matrix used for generating the second plurality of pilot sequences of the
  • the plurality 111 of look-up tables 1111 1, 1111 2, ... , 1111_L comprises look-up tables 1111 1, 1111 2, ... , 1111_L that differ from each other with respect to the M value and/or with respect to the complex matrix
  • the user communication device 112 comprises also one or more processing entities 1121 configured to execute different processing steps, except for the transmission and reception of data or pilot symbols, which are executed accordingly by the transmitting entity 1122 and the receiving entity 1123.
  • any one of the steps, which is executed by the user communication device 112 and which does not refer to data or pilot transmission, reception or storage, is particularly executed by at least one of the one or more processing entities 1121.
  • the user communication device 112 (particularly, the receiving entity 1123 of the user communication device 112) is configured to receive, for example, a signaling message comprising one or more instructions from the pilot sequence generator 1 and to pass it to the processing entity 1121 which interprets the signaling message to extract the instructions incorporated in it.
  • the instructions and thus the signaling message comprise an index of a look-up table 1111 1, 1111 2, ...
  • uplink pilot transmission is executed by the transmitting entity 1122 of the user communication device 112 which transmits the symbols of the pilot sequence selected by at least one of the one or more processing entities 1121 based on the signaling message received by the receiving entity 1123.

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Power Engineering (AREA)
  • Mobile Radio Communication Systems (AREA)
EP16805842.8A 2016-12-05 2016-12-05 Pilotsequenzgenerator und zugehöriges verfahren und kanalschätzer und zugehöriges verfahren Active EP3529960B1 (de)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/EP2016/079751 WO2018103815A1 (en) 2016-12-05 2016-12-05 Pilot sequence generator and corresponding method and channel estimator and corresponding method

Publications (2)

Publication Number Publication Date
EP3529960A1 true EP3529960A1 (de) 2019-08-28
EP3529960B1 EP3529960B1 (de) 2023-02-22

Family

ID=57482439

Family Applications (1)

Application Number Title Priority Date Filing Date
EP16805842.8A Active EP3529960B1 (de) 2016-12-05 2016-12-05 Pilotsequenzgenerator und zugehöriges verfahren und kanalschätzer und zugehöriges verfahren

Country Status (3)

Country Link
EP (1) EP3529960B1 (de)
CN (1) CN110050451B (de)
WO (1) WO2018103815A1 (de)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112564874B (zh) * 2020-11-04 2022-09-13 展讯通信(上海)有限公司 导频序列生成方法及装置

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101056152B (zh) * 2006-04-30 2010-08-04 华为技术有限公司 通用移动通信系统中的传输方法及其系统
US8705642B2 (en) * 2009-10-20 2014-04-22 King Fahd University Of Petroleum And Minerals Method for mitigating interference in OFDM communications systems
EP3031144A4 (de) * 2013-08-09 2017-03-22 LG Electronics Inc. Antennenkombination für massives mimo-schema
CN106664146B (zh) * 2014-06-24 2019-02-26 华为技术有限公司 用于无线通信系统中的多接入的方法和装置
US9774613B2 (en) * 2014-12-15 2017-09-26 Sophos Limited Server drift monitoring
WO2016180450A1 (en) * 2015-05-08 2016-11-17 Huawei Technologies Co., Ltd. Apparatus and method for controlling resource allocation in a wireless communication network

Also Published As

Publication number Publication date
CN110050451A (zh) 2019-07-23
WO2018103815A1 (en) 2018-06-14
CN110050451B (zh) 2020-12-15
EP3529960B1 (de) 2023-02-22

Similar Documents

Publication Publication Date Title
US9258041B2 (en) Methods and systems for combined cyclic delay diversity and precoding of radio signals
CN102804630B (zh) 用于在上行链路多入多出(mimo)传输中发送参考信号的方法和装置
JP5663163B2 (ja) 上りリンクの復調パイロットシーケンスを決定する方法、端末および上りリンクシステム
CA2786810C (en) A method and transmitter node for transmitting demodulation reference signal pattern
CN102437986B (zh) 参考信号映射方法及装置
CN101877689B (zh) 数据发送处理方法与装置、数据接收处理方法与装置
JP5908307B2 (ja) プリコーディング装置、無線送信装置、無線受信装置、無線通信システムおよび集積回路
CN102100045B (zh) 数据发送处理方法与装置、数据接收处理方法与装置
WO2019030894A1 (ja) 送信装置
JP2021106394A (ja) 送信装置、受信装置、基地局、端末および送信方法
CN111556570B (zh) 用于利用多址的无线通信的设备、方法和计算机程序
KR20190130315A (ko) 무선 통신 시스템에서 채널 추정 방법 및 장치
US10917221B2 (en) Base station apparatus, terminal apparatus, and communication method
WO2013168792A1 (ja) 無線受信装置、無線送信装置、無線通信システム、プログラムおよび集積回路
JPWO2010050384A1 (ja) マルチユーザmimoシステム、受信装置および送信装置
EP3529960B1 (de) Pilotsequenzgenerator und zugehöriges verfahren und kanalschätzer und zugehöriges verfahren
WO2012140847A1 (ja) 送信装置、受信装置、信号生成方法及び品質推定方法
WO2011129261A1 (ja) 基地局装置、無線通信システム、基地局装置の送信方法、及び送信プログラム
JP5909104B2 (ja) 無線送信装置、無線受信装置、無線通信システムおよびプリコーディング方法
KR101430611B1 (ko) 다중 사용자 다중 입출력 시스템에서 데이터 전송 방법 및장치
CN102439931B (zh) 数据发送处理方法与装置、数据接收处理方法与装置
JP2011155583A (ja) 無線通信装置、無線通信方法、プログラム
WO2016062066A1 (zh) 数据接收方法、发送方法、接收装置及发送装置
JP2011097411A (ja) デジタル移動体無線通信方式およびそれに用いられる基地局
KR20090105429A (ko) 무선 통신 시스템에서 코드셋 인덱스 전송 방법

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20190521

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20210416

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

INTG Intention to grant announced

Effective date: 20221031

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE PATENT HAS BEEN GRANTED

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: AT

Ref legal event code: REF

Ref document number: 1550218

Country of ref document: AT

Kind code of ref document: T

Effective date: 20230315

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602016077967

Country of ref document: DE

REG Reference to a national code

Ref country code: SE

Ref legal event code: TRGR

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG9D

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230524

REG Reference to a national code

Ref country code: NL

Ref legal event code: MP

Effective date: 20230222

REG Reference to a national code

Ref country code: AT

Ref legal event code: MK05

Ref document number: 1550218

Country of ref document: AT

Kind code of ref document: T

Effective date: 20230222

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: RS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230622

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230522

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230622

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230523

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SM

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602016077967

Country of ref document: DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20231102

Year of fee payment: 8

26N No opposition filed

Effective date: 20231123

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 20231110

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 20231121

Year of fee payment: 8

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 602016077967

Country of ref document: DE

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20231205

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230222

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20231205

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20240702

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20231205

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20231231